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MAPK Signalling (mapk + signalling)

Distribution by Scientific Domains
Life Sciences100%

Terms modified by MAPK Signalling

  • mapk signalling pathway
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    Selected Abstracts

    Neuronal p38 MAPK signalling: an emerging regulator of cell fate and function in the nervous system

    GENES TO CELLS, Issue 11 2002
    Kohsuke Takeda
    p38 mitogen-activated protein kinases (MAPKs), together with extracellular signal-regulated kinases (ERKs) and c-Jun N-terminal kinases (JNKs), constitute the MAPK family. Multiple intracellular signalling pathways that converge on MAPKs exist in all eukaryotic cells and play pivotal roles in a wide variety of cellular functions. p38 MAPKs and JNKs, also termed stress-activated protein kinases (SAPKs), are preferentially activated by various cytotoxic stresses and cytokines and appear to be potent regulators of stress-induced apoptosis. Whereas JNKs have been shown to play pivotal roles in the regulation of neuronal apoptosis, the role of p38 MAPKs in the nervous system is poorly understood. However, accumulating evidence from mammalian cell culture systems and the strong genetic tool C. elegans suggests that neuronal p38 signalling has diverse functions beyond the control of cell death and survival. This review focuses on possible roles for the p38 pathway in the nervous system, with principal emphasis placed on the roles in neuronal cell fate decision and function. [source]

    The Ca2+ -dependent protein kinase CPK3 is required for MAPK-independent salt-stress acclimation in Arabidopsis

    THE PLANT JOURNAL, Issue 3 2010
    Norbert Mehlmer
    Summary Plants use different signalling pathways to respond to external stimuli. Intracellular signalling via calcium-dependent protein kinases (CDPKs) or mitogen-activated protein kinases (MAPKs) present two major pathways that are widely used to react to a changing environment. Both CDPK and MAPK pathways are known to be involved in the signalling of abiotic and biotic stresses in animal, yeast and plant cells. Here, we show the essential function of the CDPK CPK3 (At4g23650) for salt stress acclimation in Arabidopsis thaliana, and test crosstalk between CPK3 and the major salt-stress activated MAPKs MPK4 and MPK6 in the salt stress response. CPK3 kinase activity was induced by salt and other stresses after transient overexpression in Arabidopsis protoplasts, but endogenous CPK3 appeared to be constitutively active in roots and leaves in a strictly Ca2+ -dependent manner. cpk3 mutants show a salt-sensitive phenotype comparable with mutants in MAPK pathways. In contrast to animal cells, where crosstalk between Ca2+ and MAPK signalling is well established, CPK3 seems to act independently of those pathways. Salt-induced transcriptional induction of known salt stress-regulated and MAPK-dependent marker genes was not altered, whereas post-translational protein phosphorylation patterns from roots of wild type and cpk3 plants revealed clear differences. A significant portion of CPK3 was found to be associated with the plasma membrane and the vacuole, both depending on its N -terminal myristoylation. An initial proteomic study led to the identification of 28 potential CPK3 targets, predominantly membrane-associated proteins. [source]

    Heparin regulates colon cancer cell growth through p38 mitogen-activated protein kinase signalling

    CELL PROLIFERATION, Issue 1 2010
    G. Chatzinikolaou
    Objectives:, Heparin acts as an extracellular stimulus capable of activating major cell signalling pathways. Thus, we examined the putative mechanisms utilized by heparin to stimulate HT29, SW1116 and HCT116 colon cancer cell growth. Materials and methods:, Possible participation of the mitogen-activated protein kinase (MAPK) cascade on heparin-induced HT29, SW1116 and HCT116 colon cancer cell growth was evaluated using specific MAPK cascade inhibitors, Western blot analysis, real-time quantitative PCR and FACS apoptosis analysis. Results:, Treatment with a highly specific p38 kinase inhibitor, SB203580, significantly (50,70%) inhibited heparin-induced colon cancer cell growth, demonstrating that p38 MAPK signalling is involved in their heparin-induced proliferative response. This was shown to be correlated with increased (up to 3-fold) phosphorylation of 181/182 threonine/tyrosine residues on p38 MAP kinase. Furthermore, heparin inhibited cyclin-dependent kinase inhibitor p21WAF1/CIP1 and p53 tumour suppressor gene and protein expression up to 2-fold or 1.8-fold, respectively, and stimulated cyclin D1 expression up to 1.8-fold, in these cell lines through a p38-mediated mechanism. On the other hand, treatment with heparin did not appear to affect HT29, SW1116 and HCT116 cell levels of apoptosis. Conclusions:, This study demonstrates that an extracellular glycosaminoglycan, heparin, finely modulates expression of genes crucial to cell cycle regulation through specific activation of p38 MAP kinase to stimulate colon cancer cell growth. [source]

    Anthrax lethal toxin promotes dephosphorylation of TTP and formation of processing bodies

    CELLULAR MICROBIOLOGY, Issue 4 2010
    Edith M. C. Chow
    Summary Anthrax lethal toxin (LeTx) is composed of protective antigen (PA) and lethal factor (LF) , PA is the receptor-binding moiety and LF is a protease that cleaves mitogen-activated protein kinase kinases (MAPKKs). LeTx subverts the immune response to Bacillus anthracis in several ways, such as downregulating interleukin-8 (IL-8) by increasing the rate of IL-8 mRNA degradation. Many transcripts are regulated through cis -acting elements that bind proteins that either impede or promote degradation. Some of these RNA-binding proteins are regulated by MAPKs and previous work has demonstrated that interfering with MAPK signalling decreases the half-life of IL-8 mRNA. Here, we have localized a segment within the IL-8 3, untranslated region responsible for LeTx-induced transcript destabilization and show that this is caused by inhibition of the p38, ERK and JNK pathways. TTP, an RNA-binding protein involved in IL-8 mRNA decay, became hypophosphorylated in LeTx-treated cells and knock-down of TTP prevented LeTx from destabilizing the IL-8 transcript. Cells that were treated with LeTx exhibited increased localization of TTP to Processing bodies, which are structures that accumulate transcripts targeted for degradation. We furthermore observed that LeTx promoted the formation of Processing bodies, revealing a link between the toxin and a major mRNA decay pathway. [source]